Advances have been made in the techniques and tools used in minimally invasive surgery. For example, catheters are now routinely used to access various body tissues (e.g., organs such as the heart, and vessels, such as coronary arteries). Procedures that require prolonged access to the body tissue and exchange of various tools are often lengthy due to the number of different tools that must be passed to the target site from a proximal position outside the patient's body. Methods of rapid-exchange and over-the-wire catheter systems have been developed to try to compensate for and reduce surgery times.
Rapid-exchange catheters generally include a guidewire lumen that extends for only a portion of the length of the catheter shaft. A rapid-exchange catheter may be relatively easily threaded over a guidewire, delivered to a target site, and withdrawn from the target site. Because rapid-exchange catheters do not need to be threaded over the entire length of a guidewire, rapid-exchange catheters may be relatively short in length. In some variations, a rapid-exchange catheter may be shorter in length than the guidewire over which the rapid-exchange catheter is advanced. The guidewire, in turn, may also be relatively short in length. After being withdrawn from a target site, a rapid-exchange catheter can be removed from the guidewire over which it was threaded, and exchanged with another rapid-exchange catheter, which, in turn, can be delivered to the target site over the guidewire. Some methods of removing a rapid-exchange catheter from a guidewire include withdrawing the rapid-exchange catheter over the guidewire. Other methods include using a rapid-exchange catheter with a perforated sheath, and splitting the sheath open at its perforations to remove the rapid-exchange catheter from the guidewire. The relative ease with which rapid-exchange catheters can be exchanged over a guidewire, as well as the relatively short length of rapid-exchange catheters and their guidewires, may result in reduced procedure time when such catheters are used. Additionally, rapid-exchange procedures can allow for different types of catheters (e.g., catheters having balloons of different sizes or catheters carrying different therapeutic agents) to be efficiently delivered to a target site in one-procedure. Furthermore, the use of rapid-exchange catheters in a procedure may result in a reduction in the number of operations required to complete the procedure.
Over-the-wire catheters generally include a guidewire lumen that extends along the entire length of the catheter shaft. Over-the-wire catheters may be used, for example, in peripheral procedures, such as balloon angioplasty procedures. An over-the-wire catheter may be relatively easily tracked over a guidewire and delivered to a target site. Once the over-the-wire catheter has been used to perform a procedure at the target site, it may be withdrawn over the guidewire and removed from the subject.
In instances in which multiple catheters must be delivered to a target body tissue, rapid-exchange and over-the wire techniques are particularly desirable, as they may result in reduced procedure time and/or highly accurate catheter delivery. Accordingly, additional methods and devices for advancing a plurality of catheters to a target body tissue would be desirable. Similarly, catheters configured to be advanced quickly and successively to a target body tissue would also be desirable.